Longtime Fleetwood Mac keyboardist, singer and songwriter Christine McVie, who returned to the fold in 2014 following a 16-year retirement, and guitarist, singer, songwriter and producer Lindsey Buckingham are currently in Los Angeles working on their first album together. As reported in the LA Times, the album — tentatively called Buckingham McVie, not unlike the 1973 Buckingham Nicks album that Lindsey made with Stevie Nicks — is expected to come out this May.

Fleetwood Mac drummer Mick Fleetwood and bassist John McVie are contributing to the Buckingham McVie project, but that won’t make it a Fleetwood Mac album.

It’s unclear at this point how this news impacts the long-rumored new Fleetwood Mac album, which would be their first since 2003’s Say You Will. Fleetwood told Rolling Stone last summer that the band had recorded new music with Christine McVie, but that “none of it’s with Stevie…or very little.”

“We’ve always written well together, Lindsey and I,” Christine told the LA Times, “and this has just spiraled into something really amazing that we’ve done between us.”